How to make "baked powder" effect?
You're right, a bump map from a noise texture is exactly the right solution for this problem. Add to that the right specular characteristics (high roughness in Cycles, large specular size in BI) and you're well on your way.

After that, just add a colored texture for the diffuse and it'll be pretty close. In fact, the noise texture actually provides RGB colors that you could just use for the color. (Often the noise texture is converted to greyscale because that's more useful than RGB, like with your bump map you're going to create, but it does actually use RGB values).